I am not naturally scared of hights.
(BUT) I have "programed" myself with a deliberate fear of heights to “trigger” in certain circumstances, as have many others in my industry.
I am a professional roping guide and a vertical rescue volunteer, so I am around high cliffs and buildings a lot.
We "roping experts" have a safety rule: You NEVER go within 2m of an edge unless you are attached to rope, or there is another factor that changes that distance. (eg. a railing could lower the distance, but a sloping, slippery edge could increase the safety margin.)

If I approach an edge, when I get to about 2m from it, I automatically do a safety check in my head. If I am confident that I am safe, I can proceed to the edge, and I have no fear of the height.
BUT, If I cross the 2m, and am not attached to a safety line, my subconscious freaks out for a fraction of a second. ( This starts to get annoying when i'm working on a particular one of my abseiling towers, it is a 40 tall 3mX3m tower. The top has a railing around the edge, so a safety line is not required, but this subconscious trigger is constantly activating as I move around the top of the tower, I now rig up a safety line whenever I use that tower, just to stop the trigger.)

Anyway, I'll try to stop rambling about roping and get to my point.
For some reason I feel the same short moment of fear when I see these pictures. As soon as I see one of the pictures, I feel fear for a tiny moment. Not really enough to properly scare me, but enough to notice it. Once that moment passes, I feel the same way as I do while standing on the edge of a 250m cliff….I don’t really feel anything. When I look down a large drop, I kind of stop feeling emotion, as if I am supposed to feel fear, but I don’t, and there isn’t another emotion to fill the gap. I can kind of understand this happening with heights, but these Trypophobia pictures, i'm not sure why I feel the same way.

Any thoughts/ theories/ Ideas?

Sorry for the long, rambling post. I am rather tired, and when that happens I tend to go on and on for a bit too much.